hover: 赋值语句左值显示右值结果

Author: xuhuanzy

crates/emmylua_code_analysis/src/semantic/infer/infer_name.rs

@@ -1,4 +1,4 @@
-use emmylua_parser::{LuaAssignStat, LuaAstNode, LuaNameExpr};
+use emmylua_parser::{LuaAstNode, LuaNameExpr};
 
 use crate::{
     db_index::{DbIndex, LuaDeclOrMemberId},
@@ -37,12 +37,9 @@ pub fn infer_name_expr(
         let flow_chain = db.get_flow_index().get_flow_chain(file_id, flow_id);
         let root = name_expr.get_root();
         if let Some(flow_chain) = flow_chain {
-            let mut position = name_expr.get_position();
-            // 如果是赋值语句, 那么我们使用赋值语句的结束位置来获取类型, 应用于`hover`左值
-            if let Some(assign_stat) = name_expr.get_parent::<LuaAssignStat>() {
-                position = assign_stat.get_range().end();
-            }
-            for type_assert in flow_chain.get_type_asserts(name, position, Some(decl_id.position)) {
+            for type_assert in
+                flow_chain.get_type_asserts(name, name_expr.get_position(), Some(decl_id.position))
+            {
                 decl_type = type_assert.tighten_type(db, cache, &root, decl_type)?;
             }
         }

crates/emmylua_ls/src/handlers/hover/build_hover.rs

@@ -152,8 +152,10 @@ fn build_decl_hover(
         };
         builder.set_type_description(format!("{}{}: {}", prefix, decl.get_name(), const_value));
     } else {
+        let decl_hover_type =
+            get_hover_type(builder, builder.semantic_model).unwrap_or(typ.clone());
         let type_humanize_text =
-            hover_type(builder, &typ, Some(RenderLevel::Detailed)).unwrap_or_default();
+            hover_type(builder, &decl_hover_type, Some(RenderLevel::Detailed)).unwrap_or_default();
         let prefix = if decl.is_local() {
             "local "
         } else {
@@ -251,8 +253,10 @@ fn build_member_hover(
         builder.set_type_description(format!("(field) {}: {}", member_name, const_value));
         builder.set_location_path(Some(&member));
     } else {
+        let member_hover_type =
+            get_hover_type(builder, builder.semantic_model).unwrap_or(typ.clone());
         let type_humanize_text =
-            hover_type(builder, &typ, Some(RenderLevel::Simple)).unwrap_or_default();
+            hover_type(builder, &member_hover_type, Some(RenderLevel::Simple)).unwrap_or_default();
         builder.set_type_description(format!("(field) {}: {}", member_name, type_humanize_text));
         builder.set_location_path(Some(&member));
     }
@@ -445,3 +449,36 @@ fn get_member_owner(
     }
     resolved_property_owner
 }
+
+pub fn get_hover_type(builder: &HoverBuilder, semantic_model: &SemanticModel) -> Option<LuaType> {
+    let assign_stat = LuaAssignStat::cast(builder.get_trigger_token()?.parent()?.parent()?)?;
+    let (vars, exprs) = assign_stat.get_var_and_expr_list();
+    for (i, var) in vars.iter().enumerate() {
+        if var
+            .syntax()
+            .text_range()
+            .contains(builder.get_trigger_token()?.text_range().start())
+        {
+            let mut expr: Option<&emmylua_parser::LuaExpr> = exprs.get(i);
+            let multi_return_index = if expr.is_none() {
+                expr = Some(&exprs.last().unwrap());
+                i + 1 - exprs.len()
+            } else {
+                0
+            };
+
+            let expr_type = semantic_model.infer_expr(expr.unwrap().clone());
+            match expr_type {
+                Ok(expr_type) => match expr_type {
+                    LuaType::MuliReturn(muli_return) => {
+                        return muli_return.get_type(multi_return_index).map(|t| t.clone());
+                    }
+                    _ => return Some(expr_type),
+                },
+                Err(_) => return None,
+            }
+        }
+    }
+
+    None
+}

crates/emmylua_ls/src/handlers/hover/hover_builder.rs

@@ -333,4 +333,8 @@ impl<'a> HoverBuilder<'a> {
             range,
         })
     }
+
+    pub fn get_trigger_token(&self) -> Option<LuaSyntaxToken> {
+        self.trigger_token.clone()
+    }
 }

crates/emmylua_ls/src/handlers/hover/test/hover_test.rs

@@ -17,4 +17,71 @@ mod tests {
             },
         ));
     }
+
+    #[test]
+    fn test_right_to_left() {
+        let mut ws = HoverVirtualWorkspace::new();
+        assert!(ws.check_hover(
+            r#"
+                ---@class H4
+                local m = {
+                    x = 1
+                }
+
+                ---@type H4
+                local m1
+
+                m1.x = {}
+                m1.<??>x = {}
+            "#,
+            VirtualHoverResult {
+                value: "\n```lua\n(field) x: integer = 1\n```\n\n---\n".to_string(),
+            },
+        ));
+
+        assert!(ws.check_hover(
+            r#"
+                ---@class Node
+                ---@field x number
+                ---@field right Node?
+
+                ---@return Node
+                local function createRBNode()
+                end
+
+                ---@type Node
+                local node
+
+                if node.right then
+                else
+                    node.<??>right = createRBNode()
+                end
+            "#,
+            VirtualHoverResult {
+                value: "\n```lua\n(field) right: Node\n```\n\n---\n".to_string(),
+            },
+        ));
+
+        assert!(ws.check_hover(
+            r#"
+                 ---@class Node1
+                ---@field x number
+
+                ---@return Node1
+                local function createRBNode()
+                end
+
+                ---@type Node1?
+                local node
+
+                if node then
+                else
+                    <??>node = createRBNode()
+                end
+            "#,
+            VirtualHoverResult {
+                value: "\n```lua\nlocal node: Node1 {\n    x: number,\n}\n```\n\n---\n".to_string(),
+            },
+        ));
+    }
 }